The invention relates to a parking lock arrangement for a motor vehicle transmission, having a blocking arrangement, which can be actuated between a release position and a blocking position, wherein the blocking arrangement is designed to immobilise a motor vehicle in the blocking position, and having an actuating arrangement for actuating the blocking arrangement.
The present invention furthermore relates to a motor vehicle transmission having a parking lock arrangement of this kind.
Parking lock arrangements are generally used in automatic transmissions, such as converter-type automatic transmissions, automated shift transmissions or dual clutch transmissions.
The blocking arrangement of a parking lock arrangement of this kind often comprises a parking lock wheel, which has a tooth system comprising teeth and tooth gaps. The parking lock wheel is generally fixed on an output shaft of the transmission but can also be fixed on an element of a differential. Consequently, the parking lock wheel is coupled directly to a drive output of the motor vehicle. A blocking arrangement of this kind furthermore generally comprises a parking lock pawl, which has a pawl tooth. The parking lock pawl is supported on a housing in such a way as to be pivotable between the release position and the blocking position.
Translatory systems are known for moving the parking lock pawl between the release position and the blocking position. Here, the blocking arrangement generally comprises a control member which can be moved in translation, wherein an actuating member in the form of a sliding key is supported on the control member. The sliding key is supported on the housing and, in one longitudinal position, pushes the parking lock pawl in the direction of the parking lock wheel, causing the pawl tooth to engage in a tooth gap of the parking lock wheel. In another longitudinal position, the actuating member releases the parking lock pawl, allowing it to pivot into the release position. A known practice here is to provide a retaining spring, which preloads the parking lock pawl into the release position.
Rotary systems are furthermore known for moving the parking lock pawl. In this case, a cam is supported on a shaft and either pushes the parking lock pawl into the blocking position or releases it when the shaft is rotated.
In some cases, the blocking arrangement is actuated while the pawl tooth is resting on a tooth of the parking lock wheel. In this case, provision is generally made to provide a spring arrangement between the control member and the actuating member, the spring being loaded during the movement of the control member and storing energy in order to ensure that the actuating member is moved further and can push the parking lock pawl into the blocking position if the parking lock wheel is rotated further.
In general, it is a known practice to manually actuate parking lock arrangements of this kind, e.g. by means of a selector lever in the interior of the vehicle. Alternatively, there is a known practice of actuating parking lock arrangements by means of an actuator, which can be designed as a hydraulic actuator, as an electromechanical actuator or as an electromagnetic actuator.
The actuator can act either in a translatory manner, like a hydraulic cylinder for example, or in a rotary manner, like an electric motor for example. Often, the actuating arrangements of such parking lock arrangements therefore comprise rotation/translation converters.
Document EP 1 865 237 A1 discloses a parking lock arrangement for a quad bike, in which an actuating mechanism has a cam rigidly fixed on a selector drum. A parking lock pawl is designed as a first-class lever, which, at one end, has a cam follower and, at the other end, has a pawl tooth, which engages in a tooth gap of a parking lock wheel in the blocking position. Here, the parking lock pawl is preloaded into a release position by means of a retaining spring. A further spring arrangement can be integrated into the cam follower as an energy storage device for the case where one tooth is resting on another.
Document DE 20 2008 001 760 U1 discloses a parking lock arrangement with a rotary actuation of a parking lock pawl, wherein a rotatable cam engages on a pawl back of a parking lock pawl. The cam is supported on a shaft which can be rotated by means of an actuating lever. Further parking lock arrangements with a rotary actuating system are known from DE 10 2006 043 662 A1 and DE 2101822 A.
Document DE 10 2010 054 911 A1 furthermore discloses a parking lock arrangement in which a slotted link element, which acts as an RT converter, is rotated by means of an electric motor and of a spur gear transmission. The slotted link element is connected to a sliding key of a blocking arrangement.
Document U.S. Pat. No. 2,653,689 A discloses designing a parking lock arrangement as a first-class lever, one end of which has a pawl tooth. The other end of the parking lock pawl is connected by a lever mechanism that has two further levers to an actuating rod which, in turn, is moved in translation by means of a cam.